# IV Curve Tracer

Source: https://www.instructables.com/IV-Curve-Tracer/ (by ece4901, an Electrical
and Computer Engineering capstone project at The Ohio State University).

*** Do not attempt this project if you are not comfortable working with line voltages! ***

This project builds an IV (Current and Voltage) Tracer used to teach the electrical
characteristics of a solar panel. An Arduino Uno drives a custom op-amp/DAC shield PCB;
a Windows PC application plots the captured I-V curves.

## Tools
- Drill, drill bits, Philips screwdriver, soldering iron, wire strippers, needle-nose
  pliers, banana jack test leads.

## Parts
See `Parts List.xlsx` for the complete bill of materials with vendor part numbers,
quantities, prices, and links.

## Build steps
1. **What we used** — tools and parts (see Parts List.xlsx).
2. **Order the circuit board** — PCB fabbed at Advanced Circuits (4pcb.com); design in
   Eagle CAD. Files: `CircuitDesignV4.pdf` (schematic), `REVb.zip` (Eagle board + gerbers).
3. **Drill holes for the power supply** — 4 holes for M4 machine screws through the bottom
   of the enclosure (a Hefty shoe box).
4. **Mount the Arduino Uno** — M3 PCB spacers on the power supply honeycomb cover with M4
   washers; secure the Arduino, keeping it clear of the metal cover to avoid shorts.
5. **Solder components to the PCB** — op-amps, resistors, capacitors, wires, and the DAC
   per the schematic. Thermal-compound both op-amps, fit heatsinks, solder heatsink pins.
6. **Mount the PCB on the Arduino** — plug headers into the Arduino, secure with M3 nylon
   screws; attach the 50W resistor to the honeycomb; connect GND and 24V+ to the PSU
   V+/V- terminals.
7. **Mount the Arduino + PSU in the enclosure** — M4 machine screws/washers, 8 nylon
   washers standing the PSU off the floor; mark USB, banana-jack, and PG9 gland holes.
8. **Drill holes in the enclosure** — fan mounting + airflow holes.
9. **Connect power cord and test terminals** — AC cord through a PG9 cable gland;
   ground/line/neutral to the PSU; SP+/SP- to the red/black banana test ports.
10. **Mount the fan** — fan power to PSU V+/V-, airflow directed into the enclosure.
11. **Load firmware onto the Arduino Uno** — upload `IVCurve4_27.ino` via the Arduino IDE
    (board: Arduino Uno).
12. **Install the IV Curve Tracer PC software** — `Installer.zip` (may require .NET framework).
13. **Connect the software to the Arduino** — select COM port, Connect.
14. **Connect to a solar cell** — solar panel positive to red test port, negative to black.
15. **Plot a curve** — set start/end voltage sliders, Capture; up to 5 curves per graph.
16. **Extra material** — lesson plan (`Capstone Lesson Presentation.pdf`,
    `Solar Powered Energy Demo.docx`) and PC-app source (`VSProject.zip`).